Conventionally, a connection terminal is used to electrically connect a circuit conductor provided on a board such as a printed board, to a partner member such as a connector. A so-called press-fit terminal, which is disclosed in JP 2004-127610A, for example, is known as such a connection terminal. In such a press-fit terminal, one end portion of a rod-shaped metal member is provided with a press-contact portion that is springy, whereas the other end portion of the rod-shaped metal member is provided with a connection portion that is to be connected to a partner member. The press-contact portion is press-fitted into, and is fixed to, a through hole of a board. Thus, it is possible to electrically connect the press-fit terminal to a conductor that is exposed in the through hole, and fix the press-fit terminal to the board, without using a solder.
As discussed in JP 2004-127610A, press-fit terminals are formed by stamping a metal plate. Then, a pair of arch-shaped press-contact portions are formed by punching a through hole in a central area of one end portion of a rod-shaped metal member. Such a pair of press-contact portions are formed so as to be elastically deformable in a direction that is orthogonal to the axis, and thus the rod-shaped metal member is provided with springiness.
However, many connection terminals are extremely small and have a width or a plate thickness of less than 1 mm. It is difficult to process such a terminal to form press-contact portions that have the above-described structure, and this is a cause of an increase in manufacturing costs. In addition, since both ends of each arch-shaped press-contact portion are connected to the terminal, it is difficult to secure a sufficient amount of warp. Therefore, it is inevitable that a strong insertion force is applied when the press-contact portions are inserted into the through hole, and there is also the risk of the press-contact portions shaving the inner surface of the through hole and producing metal shavings.
Considering the problems above, the inventor of the present invention previously proposed in JP 2013-149578A a press-fit terminal that includes a rod-shaped metal member, which is longitudinally rod-shaped, and press-contact portions that are formed by bringing a metal material, which is separate from the rod-shaped metal member, into press-contact with the rod-shaped metal member such that the metal material wraps around one end portion of the rod-shaped metal member. With this configuration, the rod-shaped metal member and the press-contact portions are formed using separate components, and therefore flexibility improves when manufacturing press-contact portions, and it becomes possible to advantageously form press-contact portions that have sufficient springiness (amount of warp) even if the plate thickness of the rod-shaped metal member is small. Therefore, it is possible to reliably bring the press-contact portion into press-contact with a through hole while reducing the insertion force that is applied when the press-contact portions are inserted into the through hole. Also, it is possible to prevent the problem in which the press-contact portions shave the inner surface of the through hole.
However, since the press-contact portions are formed by bringing a metal material, which is separate from the rod-shaped metal member, into press-contact with the rod-shaped metal member such that the metal material wraps around one end portion of the rod-shaped metal member, there is still room for improvement in terms of suppressing an increase in the number of components and manufacturing costs, and further improved press-fit terminals have been developed.
The present invention has been made in view of the above-described situation, and a problem to be solved by the invention is to provide a press-fit terminal that has a novel structure that makes it possible to secure an amount of warp of press-contact portions and reduce insertion force that is applied when the press-contact portions are inserted into the through hole, while suppressing an increase in the number of components and manufacturing costs.